Combined search receiver and radio jamming system



Sept 11, 1951 E. M. WILLIAMS COMBINED SEARCH RECEIVER AND RADIO JAMMINGSYSTEM Filed Jan. 25, 1945- 2 Sheets-Sheet l Riff/Vil? Sept u, w51 E. M.w|| |AMs 2,567,261

COMBINED SEARCH RECEIVER AND RADIO JAMMING SYSTEM Filed Jan. 23, 1945 2Sheets-Sheet 2 Fig. 3

V 5 /0 7"' "1 3/ 50 34 f l T d 1 .J TuN Le z: MIXER I; MIXER a Au la l lCl un mmmmmw L I/ M l I l I l JAMMING 32 35 33 l i TRANSMITTER I zosclyToR MIXER E oscxLLAToR l l V l 35 l I l I l E 1 l 37\ v 3/6 I r c lla l 0 0l] 0C l I TJI'ZE e #Ummm/2 g 7/ I I N39 l I W i l l l l 1/V lHVVENTUR Evemrd M. W/Y//ams Patented Sept. 11, 1951 COMBINED SEARCHRECEIVER AND RADIOv JAMMNG SYSTEM Everard M. Williams,'Dayton, OhioApplication January y23, 1945, Serial No. 574,163

1 Claim.

(Granted under the act of VMarch 3, 1883, as amended April 30, 1928; 3700. G. 757) The invention described herein may be manufactured and usedby or for the Goverment for governmental purposes, without the payment tme of any royalty thereon.

This invention relates to radio systems and more particularly to acombined search receiver and jammer system.

The objects of the present invention comprise the provision of animproved combined search ree ceiver and jammer system wherein a searchreceiver having a calibrated cathode ray tube screen permits thedetermination of the frequencies of any and all intercepted signalsappearing thereon, and a desired plurality of individually orsimultaneously operating jamming channels that may be individually orsimultaneously applied to any or all of the intercepted signals at theirindividual frequencies by operation of a multiple contact single centralcontrol;` and which system preserves radio silence when not activelyjamming.

With the above and other objects in view that will be apparent from thefollowing description to those who are informed in the radio art ofreceiving and jamming signals, suitable illustrative embodiments of thepresent invention are disclosed in the accompanying drawing wherein-Fig. 1 is a block diagram of a device that embodies the presentinvention;

Fig. 2 is a fragmentary block diagram of a modied part of the circuitthat is shown in Fig. 1; and

Fig. 3 is a schematic diagram in block form of a receiver jammerincorporated in the present invention.

The combined search receiver and jammer system that is illustrated inFigs. 1v and 2 of the accompanying drawing comprises a plurality ofblock circuits that are interconnected by a desired plurality ofmultiple contact switches, all of which are in the same order as shownand are ganged and operated simultaneously from a single master controlswitch I that is disposed upon a control panel or the like. A dottedline 2 indicates the ganged control among the various switches by meansof which the various block circuits shown are connected. Each switchpreferably comprises a desired plurality of individual contacts A, B, C,D, etc. The switches are associated in families bearing the sameindicating letter so that when the arm of the master control switch I ison a contact designated by a particular letter, all of the other switcharms are applied to respective contacts that are designated by that sameletter.

A panoramoscope 3 comprises a panoramic receiver provided with acalibrated cathode ray tube screen for visual indication of interceptedradio signals. The receiver may be of any one of a number of well knowntypes of apparatus such as, for example, the receivers described in 2 U.S. Patents 2,279,151;v 2,378,604 and 2,381,940 to Marcel Wallace.However, it is to be understood that the invention does not reside inthe panoramoscope 3 as such but the combination of elements describedherein,

The combined Search receiver and jammer system that is illustrated'inthe accompanying drawing comprises the panoramoscope 3 that providesvisual presentation of radio energy" that is intercepted by its antenna4. The radio energy is also fed thru a tunable receiver 9 to an audio'eproducer 5 for auditory analysis thereof when the master controlswitch I is in position A with the panoramoscope switches 6 and l andthe audio reproducer switch 8 in their respective positions A as shown.The audio reproducer switch 8 has its A position connected thru thereceiver 9 to the antenna 4to conduct the output thereof and itsothercontacts connected to,tuna ble receiver jammersl, Il, etc. The receiver9 selectively tunes in on intercepted signals that appear as pips on thecathode ray tube screen of the panoramoscope 3. At this step in theprocedure the receiver jammers I0, II, etc. are in receiving adjustment,interceptedradio energy being fed to these receivers through antennas I5and I6: The inclusion ofthe audio reproducer 5 for listening to thesignal beat frequency tones from the receiver 3 in addition to thevisual presentation of intercepted signals upon the panoramoscope 3, isfor the purposes of complete and sharp audio signal analysis. With themaster control switch l in the A positionthe respective frequencies ofall of the intercepted signals that are to be jammed are made availablefor purposesof their individual analysis and use.

A sufficient number of tunable receiver jammers I0, II, etc.` should beavailable for simultaneously jamming all of the intercepted signals thatare to be jammed at their respective frequencies. At this part of theprocedure'the operator searches for intercepted signals by use'of thepanoramoscope 3 and may monitor the signals when discovered.

Preparatory toactually jamming the intercepted signals, the mastercontrol switch I is turned to position B, whereupon all other switchesthat are ganged' therewith are also applied to their'respective Bpositions.

With all oi the switch arms of the circuit in their respective positionsB, the panoramoscope 3 and the receiver jammer Ill, thru its switch l2.are maintained in radio silence with respect t0 the antenna 4 by theinterposition of an untuned isolation stage I3 therebetween. Theisolation stage I3 prevents signals froml passing from panoramoscope 3and the receiver jammers I5 and I6 to antenna 4 but does not preventradio energy from passing in the opposite direction. The receiver`jammer IIlis then tuned to the frequency which was located by tuningthe receiver 3 9 thereon, at which frequency one of th interceptedsignals -is to bejammed by suitable means, such as by radio noiselemission or the like, from its antenna I5 at a subsequent setting ofthe master control switch I. lThe method `of tuning the receivers ismore specifically set out below'. In a similar manner the nextintercepted signal that is located by the tuning of the receiver 9 andthat is to be jammed, is tuned in by positioning all of the switchesnthat are operated by the master control switch I upon their respectiveC positions and tuning the receiver jammer II .to the frequency of thesecond intercepted signal. Suitable means, such as the antenna I6 is provided for Ythe emission of jamming radio energy Afrom the receiver j Ilat -the frequency of the 'Swed intercepted Signat As in the pre-vi-Qli$ly `des.ciiloed switch setting, the isolation stage I3vs'rves tomaintain radio silence for the panoramoscope 3 and for the receiverjammer I I when .theswtch settings are at the contact C.

V'Il he foregoing procedure is repeated, with the inclusion of asuitablenumber of additional re- 'ceilver' jammers I0, II, etc., thatconforms with the number of .individual intercepted signals that are tobe jammed, each additional receiver jarn nier beingsimila'rlyindividually tuned to the individual" frequencies of the respectiveintercepted'signals to be jammed.

Upon completion of the tuning of the receiver jammers Ill, I Ijetc. upona desired number of i,titer,cepted signals to be jammed, the mastercontrolswitch `I turned to its jamming position which, yin theaccompanying drawing is indicated by' the switch position D. When sopositioned the tuning sigrialsjsnerated by the receiver jammers `I II.,`if, .etcfaS-st .out below, which are displayed onthe panorainoscope 3when the switch I is in positions B Iand C, are removed from thepanoramoscope 3. All ofA the intercepted signals, to the individualfrequencies of which a'receiver jammer 19. ".IlI, etc. has been tuned,are simultcheously jammed by positioning the major control switch uponits position Dl When so positionedthe jammer' emission switch I1Simultaiieously excites all ofthe receiver jammers I0, il., etc. to theemission o f jamming noise over their respective antennas I5, I6, etc.so that all intercepted signals to which the receiver jammers i IU, VII, etc. areindividually'tuned may be jammed at .one thneand whollywithout priorl warning to theI source o fthe intercepted signals.

`When jamming intercepted signals, the panoramoscope. 3 and the audioreproducer l5 are -preferalcl-y.,A although not necessarily,non-receptive since the. switch positions ID and 8D are open. Thevisolation `stage I3 is preferably. protected against the violence ofthel jamming operation i n any suitable. manner, asv by making theswitch position IZrD opener the like. Since. the switch ignition UDische jamming position for this switch Il.r and'since vit is desirablethat radio silence be maintained,priorA4 to the actual jamming operationthe otherpositions of the jamming Snitch llereopen- In operation thevarious switches of the set are Sii-i111.1. t 1uo11s1vv placed in theirrespectiven positions py placing the. master control switch I in iis Leposition. When so connected a time sweep is maintained upon the screenof a cathode ray tubey that forms a part of thev panoramoscope 3.Signals that are intercepted by the antenna 4 and that` arev within thefrequency range of the panoramoscope 3 appearas deflections of. or pipsrising from. the, time sweep base line on the cathode ray tube screen ofthe panoramoscope 3, which screen is calibrated so that the variousfrequencies of the individual signals are deter= minable tlier'efrom;

The selective jamming of an individual signal or the simultaneousjamming of a plurality of signais is then accomplished by turning themaster control switch I to its B position and tuning an .oscillator 32shown in Fig. 3 in the receiver jammer I0 whereby the pip generated inresponse to the tuning signal from receiver jammer I0 is moved laterallyinto optical registration with a pip `:generated .by an interceptedsignal or in other words, to the frequencyof a signal to be jammed,where .the device is limited to a single receiver jammer I0 with theomission of the switchC positions and theirY connections, or bysuccessively repeating the above process for the various signals thatare to be jammed where a plurality of receiver jammers I0! II, etc. arein the device. With the various jammers i0, I I, etc. tuned to therespective frequencies of a plurality of signals. to be jammedsimultaneously, the master control switch I is placed on its last orjamming position, a s `shown at position D on switch II whereupon Ythesending antennas I5, I6, etc. simultaneously emit jamming radio energyon each of the fre quencies of each of the signals being jammed.

Each of the receiver jammer circuits I0, II., etc. comprises acombination search receiver yand jamming transmitter set as shown inFig. 3. The search receiver is a superheterodyne circuit comprising amixer 30, a. tunable circuit 3l and a local oscillator 32, both Acircuit43| and oscillator 32 manually tunable by a ganged control 39 by means.of which the receiver is tuned on an intercepted signal that is to bejammed, The individual .search receiver also comprises a weak signalfixed frequency oscillator 33 that beats with .the output Signals frommixer 30 in mixer gli, this mixer 34 being so constructed that itaccepts .only signals rat frequencies in a narrow band about thefrequency of oscillator 33. Oscillator 3 3 is tuned to the intermediatefrequency o f the Search receiver. This oscillator -33 is used inconjunction with an intercepted signal to tune the search receiver bythe method of zero. beat by Vconnecting the audio reproducer 5 tothemixer 34 through switch 8. The individual search receiver is alsoprovided with an extra mixer 35 wherein the local oscillator 32 and theoscillator 33 signals. are combined into a tuning signal whichreproduces the. signal frequency to which the Search receiver is tuned.In accordance with standard practice, an adjustable` tuned circuit 31 isinterposed inv the routput circuit of mixer 35 to pass .thetuning signalof desired frequency, since vdiierence frequency componentsy apr. pearthe. output of mixer 35. The circuit 31 is tuned in connection with thetuning of oscillator 3 2, as is shown in Fig. 3. This signal appears ata special tuning signal terminal 336 of the. set but is shielded fromappearing elsewhere in the Sech receiverl it is, desired to connect theindividual set to jammer transmitter operation, this signal is empliedin a jamming transmitter 38, shown in Fig. 3, to supply the carrier ofthe jamming trans,- mission, this carrier being modulated by noisesignals in the transmitter 38 in any well known manner, In this mannerthe transmitting portion of the setA emits a signal of the samefrequency. asv that toV which the search receiver portion of the set hasbeen, tuned. The intercepted signal is.

jammedvery quickly after it is intercepted. This type of set is rapid inoperation since no additional time is required to tune the transmitterafter the search receiver is tuned on the intercepted signal. Thecombination of search receiver and jammer system in connection with thepanoramoscope 3 has the advantage of displaying all of the signals thatmust be jammed so that it is impossible for an operator to pass over asignal unnoticed when tuning the individual receiver jammers I0, II,etc. panoramoscope 3 permits an operator to monitor continuously all ofthe intercepted signals that appear over the frequency band that iscovered by the panoramoscope 3.

The positions B, C, etc. of the switches i, l2, etc., permit the placingof the tuning signal of the receiver jammers It, ll, etc., into thepanoramoscope 3 so that the receiver jammers I0, II, etc. may be putapproximately into tune rapidly with the intercepted signals to bejammed and the fine tuning adjustment completed in the receiver jammersIii, Ii, etc. with the assistance of the zero beat method utilizing thelaudio reproducer 5.

A unied control is provided by the single master control switch l,whereby the various circuit manipulations are effected. As previouslystated, the jamming transmitters preserve radio silence except whenactually jamming intercepted signals. Toward this end tuned radiofrequency stages such as tunable circuit 3l are provided in the variousreceivers in the device and the tuning signals in the receiver jammersets Iii, I I, etc., are shielded internally of the sets, which,together with the untuned isolation stage I3, prevents the i tuningsignals of the receiver jammer sets lil, II, etc. from being emittedfrom the panoramoscope antenna 4.

One modication of the disclosed circuit has been previously referred towherein but a single receiver jammer Ill is provided with the omissionof the C positions of the various switches and the connections thereto.

Another modication of the disclosed circuit is shown in fragmentary formin Fig. 2 of the accompanying drawing, with its position in the circuitthat is shown in Fig. 1 indicated by the showing of the parts thereofwith which the modification parts are associated.

In the fragmentary circuit that is shown in Fig. 2, the master controlswitch I has a desired number of additional contacts added thereto asindicated by the additional contacts added thereto as indicated by theadditional contact E. The switch Il in the circuit shown in Fig. 1 hasbeen replaced by a switch I8 that has a desired number of contacts inconformity with the number of contacts on the master control switch I.The arm of the switch I8 forms a common conductor from Which leads thatare connected as shown, tap

off to a desired plurality of receiver jammers It, I I, etc., that areindividually provided with sending antennas I5, I6, etc. The contactsfor receiving signals on the panoramoscope 3, and for tuning the spotreceiver 9 and the receiver portions of the receiver jammers I0, II,etc. upon signals that are to be jammed, are as previously explained. Inthe installation shown, the contacts A, B, and C of the switch I8 areopen. Of the remaining contacts, the contact D is connected with thereceiver jammer I and the contact E is connected with the receiverjammer II. Additional contacts would be connected with additionalreceiver jammers.

In other words, the

In operation, the tuning in of the panoramcscope 3, the spot receiver 9,and of the receiver jammers Iii, Il, etc., would be as previouslydescribed. When ready to jam, the master control switch I would beturned to the contact D, thereby placing the contact engaging end of thearm of the switch I8 in electrical engagement with the switch I8 contactD. The making of this contact causes the receiver jammer Iii to emitjamming radio energy on the frequency to which the receiver jammer I0 istuned from its sending antenna I5. In a similar manner the closing ofthe contact E of the switch I8 causes the receiver jammer I I to emitradio energy of the frequency to which it is tuned from its sendingantenna I6. In this manner one or a plurality of intercepted signals maybe separately jammed independently of other signals to be jammed.

It is to be understood that the particular arrangement of components andparts of the circuits and the particular connections therebetween thathave been illustrated and described herein have been submitted for thepurposes of showing and describing illustrative embodiments of thepresent invention and that various modications and changes may be madetherein without departing from the scope of the present invention.

What I claim is:

In a radio jamming system, a panoramic receiver including meansproviding a visual presentation of all intercepted signals within aselected range of frequencies, a plurality of tunable search receiverjammer transmitter sets each of which generates a tuning signal and abeat signal, first means for selectively electrically coupling saidtuning signal of each of said sets to said panoramic receiver forvisually presenting said tuning signal simultaneously with saidpresentation of said intercepted signals, whereby visual alignment ofsaid tuning signal with a selected one of said intercepted signals maybe effected by tuning the selected set so that the frequency of saidtuning signal will approximate that of said se- A lected interceptedsignal, an audio reproducer,

said reproducer being selectively electrically connected to saidselected set by said first means, said reproducer being responsive tosaid beat signal generated by the set to which it is connected duringsaid tuning to aid in tuning said set by the method of zero beat, atunable receiver being coupled to the input of said panoramic receiver,said audio reproducer being selectively coupled by said rst means tosaid tunable receiver for aurally presenting selected signals, and meansfor switching said sets to transmitter operation, said last mentionedmeans being operable to couple said tuning signal in each of said setsto means for transmitting a jamming signal at the frequency of saidtuning signal and said switching means also operable to disconnect saidsets from said panoramic receiver and from said audio reproducer.

EVERARD M. WILLIAMS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,363,583 Gilman Nov 28, 19442,412,991 Labin Dec. 24, 1946 2,418,139 Preisman Apr. 1, 1947

